Spark-plug.



- 'JULIA nAMsmAcK, FRANKLIN RnvIs'rAcK, ANI) ERICH marismas, or MILWAUKEE,

WISCONSIN. f

described.

SPARK-PLUG.

merma c Specification of Letters Patent.

'Patented nee. i7. iets.

Application filed May 29, 1916. SerialiNo. 100,472

To n.72 whom 'it may concern: Be it known that'we," JULI-a RAMs'rACit, FILNNKLIN' RAMSTACK, and ERICH RAM- sTAcn, citizens of the United States, and residents of Milwaukee, in the county of Milwaukee and State of lllisconsiln'. have invented new and useful Improvements in SparlePlugs, ot'which-the following is a description, reference being had to the ac chamberbeing the ignition chamber and so constructed as to permit the spark to pass lbetween either of two points and the upper chamber being what ma)7 be called a com piession chamber to prevent the ingress of soot therein and consequently lprotect the portion of the plug adjacent the insulated core from short circuiting.

The inventionfurther consists in the several features hereinafter set forth and more particularly7 defined bv claims at the conclusion hereof.

Figure 1 is a vertical sectional view through the plug embodying the invention:

Fig. 2 isa section ltaken on .line 2:2 of Fig. 1: '1"

Fig. 3 is a section taken on line 3 3 ot'l Fig. 1.

. n general, the spark plug comprises a casing Je adaptedto be secured to the cylinder of an internal combustion engine. anA

electrode 5 having 'a portion thereof dis-- posed within the casing l and insulated therefrom and detacliabl)7 connected vthereto contact members 6 and 7 within the casing l and spaced' from the lower portion of the electrode to forni upper and lower spark gaps, the contact members, together with the casing 4, also forming upper and lower chambers 8 and 9 for purposes hereinafter The casing -l consists of a cylindrical ineinb'er haring a threaded portion 10 for detachably securing .it to the c vlinder ot chamber within the casing of the plug, the lower lthe engine, an end portion 11 to facilitate the securing of'tlie casing in 'place within said engine QYlinder, an upper threaded portion 12 and 'aA lower portion 13 provided with a plurali@Y of apertures 11 in the sides thereof to establish communication'between the 'interior of thev cylinder and the lower chamber 9.

The electrode 5 is of usual construction consisting of a straight piece of wire which, is insulated from the casing 11 b v means of a core 15 of' suitable -insulating material.

such as porcelain` the electrode extending through a cylindrical bore 16 in the' core lo and having a threaded upper end 1T for receiving the internally threaded bindingpost 18l and its cooperating washer 19 to which the wire, not shown,- leading to a suitable source of electrical energy is connected.

The electrode 16 is detaehablv secured with-v in the casing 11 b v means which secure the core 15 to the casing. ot' a nutl 2O having threaded engagement withjthe threaded portion 12 of the casing and provided with an 'inwardly extending annular flange 'portion :21 which isadapted to engage a washer ring 22 seated on a shouldered portionQB ofthe core 15 and' to clamp the core 15 between the said shouldered portion and the annular shouldered portion 24 in the' casing which' contacts with a. washer disposed between it and a lower shoulder 26 on the core 15. 1n thisl wav the core 15 is detachabl'v seated in the upper part of the casing and the electrode .'i carriedftherebv is thus properliv positioned with respect to the casing..

The upper contact member t3 consists of an annular ring which rests on an annular shoulder QT-in theend portion 1? of the casing and-which lmav be secured thereto in an)v suitable manner .such as bv punching the edges of'the member (3 so as to strike up projections-which engage with 'the 'interior wall lof efcasing. The electrode 5 rims through ther opening 28 of the member 6 and is spaced therefrom so as to t'orin the,v

upper spark gap.v The contact member 6 also serves to divide the lower part of the la'r plate provided with a plurality ing -iianges 30 at the `lower end tif-,the casing'.

This plate may be secured in any suitable.

This means consists` and core is kept clean.

chamber 8 vacts as a heat insulator to prevent manner to the casing, Jfor'instance, in the same manner as that of securing the plat In this connection it will also be unde i od that the plates 6 and T may be made integral with the casing Without departing from the spirit of the invention. The lower` portion 31v of the electrode 5 projects through the opening 32 in the plate 7 and is spaced therefromto form the lower spark gap.

The upper compression chamber 8 is formed by the sides ot' the casing, the plate 6 and the end of the core 15 and the lower ignition chamber 9 is formed by the sides ot' the casing and the plates 6 and 7. It will be noted that the volume of the chamber S is greater than the chamber 9. The apertures 29 in thc .plate 17 and apertures 14 in the` casing permit` the gas to enter and escape from the chamber 9. Y

In the construction above described it will be noted that a spark may be had across the electrode 5 to the plate 6 or across said elec! trode to the plate '7 and in case the charge should not be fired from a spark across the plate 7, it willfire across the disk 6. The apertures 14 and 29 are provided, as previously pointed out, t0 permit the gas to enter and escape trom the lower chamber 9 and the passage ot gas through said chamber cleans it out and consequently keeps the lower end of the electrode clean and the plate 6 always acts to keep foreign matter away from the .upper chamber. In tact, with the present construction, there is no liability for any collection of soot within the chamber 8 and thus any tendencv of the plug to short across the lower portion ot the core 15 is prevented and the said electrode Furthermore, the

the high explosive .temperature in the combustion'chamber of the engine from acting directly upon the porcelain. In case oil is used in the cylinders it frequently happens that on explosion, the oil splashes up into the plug and forms a circuit across the insulation, but with the present invention the plate 6 electually prevents this occurring for the oil'can only splash up as far as the first chamber and this chamber is self-cleaning by the passage of the explosive mixture therethrough. In the constructionrabove described, attention is also called. to the fact that when the explosion within the cylinder, the light products ot combustion vsolid pass 'upthrough the chamber 9 into the chamber 8 and forms a pressure area within said chamber 8 which prevents the heavier products of combustion from entering said chamber and through. the accumulation ot' matter thereinf-A short-circuiting the plug.

The invention thus .exemplifies a spark the bore, `an electrode carried by said coreA Y and having a portion extending down through the bore below the core, a contact member connected to said casing within the bore and. spaced from said electrode to form a spark gap, said Contact member dividing said bore into an unobstructed upper pressure compartment and a lower ignition com-.

partment, the volume of the upper compartment being greater than that of the lower compartment, a contact member at the bottom of the casing and cooperating with the electrode, and means for permitting the passage of gas through the lower compartment.

'2. A spark plug comprising a casing having a bore therein, an insulated core having its lower end seated within the upper end ot the bore, a tubular electrode carried by said core and having a portion extending down through the bore, an annular contact plate disposed within the bore and spaced from said electrode to forni a spark gap, said plate dividing said bore into an unobstructed upper pressure compartment and a .lower ignition compartment. the volume of the upper compartment being greater than that of the lower compartment, and an apertured plate secured to the casing and forming the lower end of the ignition compartment and spaced from the electrode to form a spark gap.v

In testimony whereof, we'afHX our signatures.

JULIA RAMSTACK. l FRANKLIN RAMSTACK. ERICH RAMSTACK. 

